Engineering note
Exact recall belongs to the exact tiers.
Recall
Exact and scale tiers are different contracts.
fp32 and fp64 rows are exact-recall tiers within their validated scale envelopes. fp16 is a scale tier with measured recall bounds, not a universal exact-recall contract.
That distinction matters for compliance, healthcare, finance, and scientific buyers, especially when comparing real embeddings with synthetic low-rank scale-envelope rows.